The present invention relates generally to can end handling apparatus and more specifically to a method and apparatus capable of receiving a continuous flow of can ends either in stacked or unstacked relation, and delivering a stack of accurately precounted can ends to a bagging station for either manual or automatic bagging.
Briefly, can manufacturers fabricate can bodies and can ends for sale to canneries, or the like, wherein the product to be packaged is disposed within the can body and sealed therein by securing to the open end thereof a mating can end. Seldom does the producer of a can product manufacture his own cans, and as such, he will purchase from a can manufacturer the necessary number of can bodies with one end attached, and a like number of separate but mating can ends for subsequent assembly. It is therefore necessary that the number of separate can ends delievered to the customer be approximately equal to the number of can bodies delivered, so that production runs are not interrupted due to an insufficient supply of ends.
In practice, the can bodies, which may have one end thereof already closed with a can end, and can ends, for closing the other end, are delivered separately. The can ends are shipped in elongated kraft paper bags. Preferably, each bag shipped should contain a preselected number of ends. The size of the bags may vary from manufacturer to manufacturer and from customer to customer. Normally the can ends are shipped in lots of 300 or more. It is prefereable that, regardless of the size of the bag, a preselected number of can ends be disposed in each bag so that an accurate count of the can ends delivered and the can ends on hand can be determined. As the number of can ends ordered generally run into the millions, manual counting of the can ends disposed in each bag is impractical. Can manufacturers, in the past, have employed various methods of providing a general count of can ends in each bag, these methods are extremely imprecise and have resulted in serious logistical problems.
The technique normally employed in present day bagging to provide some semblance of an accurate count involves the correlation of a measured distance to a given number of ends. That is to say it is determined that X number of ends in stacked relation should be Y inches long. Accordingly, can ends are delivered to a trough in horizontally stacked relation and engaged against an abutment means. A pivotally mounted adjustable separator device in the form of a finger or thin blade is disposed a given distance (Y) from the abutment means against which the can ends rest. The separator device is moved toward the trough to engage the stack of can ends therein, thereby separating from the entire stack a portion thereof having a given length (Y), the separated stack portion presumably containing the desired number of ends. The separated portion is then removed from the trough and delivered to a packaging station wherein the ends are disposed manually within bags.
As can be appreciated, the above discussed method is extremely inaccurate for a number of reasons. First of all, it is essentially a manual operation and operator fatigue, inattentiveness or lack of concern will introduce error. Furthermore, the number of ends disposed within the confines of the separator means and the abutment means depend upon the degree of engagement or compression of the can ends. It has been found in practice, that the number of incidents of an undercount of can ends far exceeds an overcount.
When a manufacturer of a canned product receives a shipment of bagged can ends, which often number in the several millions of ends, a random sampling is taken of the bags and a handcount is effected as to the sample bags. The average shortage per bag is then determined as to the sampling, and this figure is employed as a statistical average per bag for the entire shipment. For example, an order of three million can ends, packaged 300 per bag, will be shipped in 10,000 bags. Assuming further, that a sample count determines an average shortage of two ends per bag, the customer will immediately request shipment of an additional 20,000 can ends to cover this average shortage. Canning plants are generally run on a substantially continuous basis and cannot afford disruption of a production run due to a shortage of can bodies or can ends.
These additional or make-up orders are extremely troublesome and costly to can manufacturers. While each makeup order is relatively small, the total number of such orders is a factor which increases the manufacturing cost of cans. For example, each makeup order must be handled individually which is a time consuming and costly procedure. Accordingly, it can be seen that there exists an urgent and real need for apparatus that can provide an accurately precounted stack of can ends for bagging, whether the bagging is accomplished manually or automatically. Of course, where automatic bagging is involved the saving is even greater.
The bagging of can ends, which, as mentioned above, is now almost exclusively a manual operation, is an area which produces exceedingly high labor costs. This results, due to the fact that the present day can manufacturing apparatus can operate at speeds far in excess of that achievable by an operator. This manual bagging operation requires the operator to select a bag, slip it over a hollow bagging horn, and then manually push the counted stack of can ends into the bag, remove the bag and place it on a pallet. It can be seen that the number of bags that can be handled per hour or per shift by an operator is somewhat limited. With high speed can manufacturing lines, as are in operation presently, the bagging operation amounts to a bottleneck which can only be alleviated by employment of relatively large numbers of operators. In addition to the excessive labor costs, employment of a number of individual operator stations necessitates machinery for diverting the ends from a processing machine to the various bagging stations. This machinery further increases operating costs.